[技术]Arizona眼睛模型 [复制链接]

简介 #a}fI  
WOgbz&S?J  
人眼光学模型可用来设计眼科用设备，光学系统注定了要与人眼一起使用。本文演示了这样一个模型：Arizona眼睛模型，在Jim Schwiegerling教授的书中有详细描述：《Field Guide to Visual and Ophthalmic Optics》。AZ眼睛模型达到了基于平均临床数据所决定的轴上和轴外像差等级。FRED文件包含了此眼睛模型及几个用来分析它的光源，并包括一个基于想要的屈光度来调整模型的内嵌脚本。 'lIT7MK  
6aMqU?-
 
模型 M^g"U`  
`n5|4yaG~  
模型的定义如表1种所示，由半径、圆锥常数、折射率、阿贝数、到下一面的距离等一系列表面组成。一些参数由屈光度（A）来决定。 &x;v&  
<=jE,6_|  
/=Q7RJ@P  
在FRED中使用0屈光度来创建的，光瞳加在了透镜的前面。材料是创建一个新的材料并选择类型“Model Material”,输入的参数是nd和vd. npbNUKdz  
qIO)Z   
光源 ze,HNFg@>  
`wk#5[Y_  
多个光源定义来分析该模型的不同特性。图1显示了所以的光源和提示信息告诉您他们可以用来做什么。 W@pVP4F0xM  
wl5!f|  
PiAA,  
z@<`]  
除了“Letter F”之外的所有光源的光线位置设定在了孔径光阑位置处，并增加了pre-propagation distance= -8。尽管光线在光瞳处创建，规定的传输方向相对于光线位置在pre-propagation distance之后。这意味着光束沿着Z轴在眼睛的前面以平行光入射，而不是在光瞳处入射。 #^Sd r-   
-Z6ot{%  
在往下看是内置的脚本用来修改屈光度，使其为4（250mm），光源“Letter F”在视网膜处生成一个字母为F的图像。绿色的光线聚焦的非常好而红色和蓝色光线有一点的模糊。使用Positions Spot Diagram分析工具来观察最为合适。 {!6
!z,  
u49/LtB\  
Mx$VAV^\  
pB
macFP  
视网膜的散射 BnAia3z  
ogjm6;  
在散射文件中，有一个名为“Retina surface”的72%的反射型朗伯散射，它为视网膜的散射提供了一个粗略的近似。为了模拟来自视网膜的散射，改变自定义元件“Eye ball” 下的视网膜的表面从“halt all” 到”Allow All”。并使几何中“plane”可追迹。 ot-!_w<  
3go!P])  
zy5@K)  
g-')|0py  
注意在视网膜的表面有散射重点采样规格定义，在“Scatter”标签的底部可获取该信息。“toward pupil”指定散射光朝向光瞳，半角度10度。 l+YpRx/T\  
 h}+,]^  
WWq)CwR  
<\Y>y+$3  
脚本 ("H:T?4Qs  
Kw925@W  
内置脚本使用对话框显示屈光度和光瞳直径的数值设置。使用FRED Basic脚本创建和使用对话框非常容易。图6显示了如何获取用户自定义对话框，如下图所示： PO |p53  
O
L=IUg"  
(AR-8  
G^ n|9)CVW  
如果“OK”按钮按下，将会核对对话框下面的代码行，如果点击取消则脚本终止。然后输入的参数赋予变量，如果此处是保留为空白，则使用默认值。因此，如果没有值输入并点击“OK”按钮，则脚本是以屈光度为0，光瞳直径为4mm来运行的。 ;~/  
余下的脚本计算与屈光度有关的所有参数。 (Rs<'1+>  

jd(=? !_  
分析 G7zfyw}W  
"FG6R'  
屈光度为4，光瞳直径为4mm，字母F点在视网膜上所成的像。 a>""MC2  
T[ky7\  
LH<--#K  
脚本代码 5#WZXhlc}  
J+Y&a&j.  
Option Explicit     'Remove this to enable non-dimensioned variables to be used. }Y<(1w  
M|Z]B<_x  
Dim entity As T_ENTITY J,P7k$t2vv  
Dim op As T_OPERATION kiqq_`66  
Dim mat As T_MODELMATERIAL Kd^ ._  
Dim A As Double ]lm9D@HMC  
Dim pupilDiam As Double @bD,^3U  
Dim eID As Long ){8^l0b  
Dim parID As Long @GjWeOj]  
Dim count As Integer B4U+q|OD#  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double H( cY=d,  
Dim tlens As Double, nlens As Double UW)k]@L  
Dim curv As Double, conic As Double gzl_ "j  
Dim ok As Long `q4\w[0+p  
AL,|%yup  
Sub Main =BNmuAY7  
3#5sj >  
    '用户输入对话框 ~~wz05oRG  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 2b3x
|9o8  
        TextBox 220,21,40,21,.TextBox1 'default: 0 cAIS?]1  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 mlIc`GSI  
        OKButton 40,91,90,21 DAc jx:~  
        CancelButton 190,91,90,21 L88
oh&M  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 b:W]L3Z8  
        TextBox 220,49,40,21,.TextBox2 'default: 4 `[Z?&'CRQ  
    End Dialog 5b|_?Em7  
    Dim dlg As UserDialog njvmf*A?S  
O+z-6:`  
    ok = Dialog (dlg) H:p(C?tk{  
RwY) O5  
    If ok=0 Then    'cancel button was pressed 5?6ATP:[  
        Print "Execution cancelled." /:C"n|P7Z  
        End 0( /eSmet  
    End If g[:5@fI#*  
KHdj#3<AR  
    'Assign accommodation and pupil diameter & use defaults if field left empty &ec_jxF  
    If dlg.TextBox1 = "" Then fZXd<Fg+  
        A = 0           'Default accommodation >Li ~Og@  
    Else ,!u^E|24  
        A = CDbl(dlg.TextBox1) rP#@*{";  
    End If 1~ZDHfd
5  
tA'i-D&  
    If dlg.TextBox2 = "" Then )3z.{.F  
        pupilDiam = 4   'Default pupil diameter /kNr5s  
    Else pE15[fJ`  
        pupilDiam = CDbl(dlg.TextBox2) 5.5dB2w  
    End If W6~<7  
a0
8B8  
    Print " " qlDL
Z.  
    Print "Accommodation = " & A & " Diopters" ib uA~\5  
    Print "Pupil Diameter = " & pupilDiam & " mm" f)N67z6  
dp_J*8  
    ' Calculate new parameters with accommodation 5M*q{kX)  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness 
b%T-nY2  

}RW4  
    Rant = 12.0 - 0.4*A                     'Radius of anterior lens e`8z1r  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens e#&[4tQF  
9$S2:2(G  
    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens b@5&<V;r2  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens xI_WkoI  
s9O] tk  
    tlens = 3.767 + 0.04*A                  'Lens thickness ~+^,o_hT  
/"Rh bE  
    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction HHtp
.;L/  
y$\K@B4  
    'Adjust parameters to account for accommodation (|O
;Ci  
 '6 w|z^  
    '************************************************************************* Gs*ea'T)  
    'Aqueous thickness (Position of Lens) bu@Pxz%_  
    '************************************************************************* _%<7!|"  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) ki}Uw#  
    GetCustomElement eID, entity 6^|bKoN/ f  
ux{OgFfi  
    parID = FindFullName( "Geometry.Arizona Eye" ) -c|O!Lc-  
cDE?Xo'!  
    ' Delete any shift(s) in z F fl`;M
 
    count = 0 C8NbxP  
    While GetOperationCount(eID)>count aU#8W.~  
        GetOperation eID, count, op %'^m6^g;  
        If op.Type="ShiftZ" Then RTF{<,E.UX  
            DeleteOperation eID,count REFisH-  
            count=count-1 l  4~'CLi  
        End If F"B!r-J  
        count=count+1 mb\vHu*53  
    Wend :gQc@)jZ(*  
Fi*6ud\n!  
    'Set new shift in Mzxz-cE  
    op.Type = "ShiftZ" /R@(yT=t  
    op.val1 = taq x1A^QIuxO  
    op.parent = parID =X+DC&]%!  
    AddOperation eID, op |a^ydwb  
    Print "Set aqueous humor thickness = " & taq-0.55 1Rl`}7Km  
!K`;fp!  
    '************************************************************************* 1F[; )@  
    'Radius and conic constant of anterior lens jzzVZ%t  
    '************************************************************************* %y8w9aGt  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) Td8'z'  
    GetConic eID, entity, curv, conic f_;3|i  
5zEl`h  
    SetConic eID, entity, 1/Rant, CCant r("7 X2f  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant KJ'MK~g  
?A2EuvQH]  
    '************************************************************************* DYzVV(_J"  
    'Radius and conic constant of posterior lens /0@}7+&  
    '************************************************************************* %}$6#5"';  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" )
xbn+9b  
    GetConic eID, entity, curv, conic :q6hT<f;  

}8x[  
    SetConic eID, entity, 1/Rpost, CCpost EHo"y.ODg  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost 2hU4g e?6  
)OjbmU!7  
    '************************************************************************* 6p1TI1(  
    'Lens thickness (Position of posterior lens surface) X Phw0aV  
    '************************************************************************* cH2 nG:H  
B=n]N+  
    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) ncS^NH(&  
R`s /^0  
    ' Delete any z-shift(s) Of:e6N  
    count = 0 +cjNA2@  
    While GetOperationCount(eID)>count KZD&Ih(vC  
        GetOperation eID, count, op gB
kb0  
        If op.Type="ShiftZ" Then sy>Pn  
            DeleteOperation eID,count p&ow\AO  
            count=count-1 &;%+Hduc  
        End If cl)MI,/>  
        count=count+1 JTz1M~  
    Wend B5tJ|3!  
%iJ6;V4  
    'Set new z-shift Uhg[#TUK  
    op.Type = "ShiftZ" IP{Cj
=  
    op.val1 = tlens dIM:U:c  
    op.parent = parID #2cH.`ty  
    AddOperation eID, op ^P{'l^CVX  
    Print "Set lens thickness = " & tlens 6E_YQbdy  
[3/P EDkw  
    '************************************************************************* .cu5h  
    'Lens index of refraction aD3$z;E  
    '************************************************************************* lXB_HDY  
    eID = FindMaterial( "Lens" ) .X:{s,@  
    GetModelMaterial eID, mat tQ|b?3  
IM +Dm  
    mat.Nd = nlens HkrNh>^=  
    SetModelMaterial eID, mat poXkH@[O  
    Print "Set lens index of refraction = " & nlens sPd5f2'  
A;Zg:  
    '************************************************************************* Ylo@  
    'Pupil diameter ~zRW*pd  
    '************************************************************************* [r]USCq  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) d628@~Ekn  
R[_7ab]A  
    'Adjust pupil diameter (trimming volume inner hole) oh:t ex<  
Nwu#,f=X  
    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" +vYm:  
m{V
@Om  
    ' Adjust pupil location to just in front of the lens hs/nM"V  
    parID = FindFullName( "Geometry.Arizona Eye" ) px-*uh<  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) +}^} <|W6  
    count = 0 "`&?<82  
    While GetOperationCount(eID)>count 65<p:  
        GetOperation eID, count, op ly^F?.e-  
        If op.Type="ShiftZ" Then }[75`pC~O  
            DeleteOperation eID,count F.@yNr"  
            count=count-1 pwu5Fxn)  
        End If lGcHfW)Y  
        count=count+1 Kvk;D ]$  
    Wend { !FrI@  
    op.Type = "ShiftZ" ]-ZD;kOr  
    op.val1 = taq-0.01 kB~:HQf  
    op.parent = parID 3$y]#
L  
    AddOperation eID, op 4!monaB"e  
3mBrnq]j>  
    Print "Set pupil diameter = " & pupilDiam I/Vlw-  
rj:$'m7  
    'Update AZ Eye subassembly Description '!y ^  
    eID = FindFullName( "Geometry.Arizona Eye" ) !\"C
<*5  
    GetEntity eID, entity nbOMtK  
    entity.Description = "Accommodation = " & A & "D" xy|;WB  
    SetEntity eID, entity Q2tGe~H  
AS8T!  
    Update y2<g
96  
    Print "DONE!" *^NC5=A(
d  
    
R)<>} y  
End Sub 2 3>lE}^G  
kmP0gT{Sj  
如果屈光度是4，光瞳直径是4，则会输出如下数据： i#Wl?(-i  
<rCl  
Accommodation = 4 Diopters ff{ESFtD  
Pupil Diameter = 4 mm i5)trSM|  
Set aqueous humor thickness = 2.81 ;vd%=vR  
Set anterior lens radius = 10.4 and conic constant = -2.375869 9g 2x+@5T^  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 .j;My%)?p  
Set lens thickness = 3.927 OCRx|  
Set lens index of refraction = 1.42672 {N _v4})  
Set pupil diameter = 4 2o/AH \=2  
DONE! %3kqBH!d